Question Bank for Power Conversion Technique.

  1. Define and explain firing angle in respect of single phase and three phase converters.
  2. What are the different types of single phase half controlled converters compare them.
  3. A single-phase bridge converter feeding power to R load is triggered at an angle α = 120°. Draw load voltage, load current, and thyristor voltage waveform.
  4. A single-phase bridge converter feeding power to R load is triggered at an angle α = 120°. if load has some inductance, draw load voltage and load current waveform (assume current to be discontinuous)
  5. A Single phase full wave converter operated from 120 V, 50 Hz supply for resistive load of 10 ohm. If average output voltage is 25% of maximum possible average output voltage, find
    • (i) firing angle,
    • (ii) average output current.
  6. Explain single phase half wave controlled rectifier with RLE load. Draw output voltage, output current waveforms for α=60°for discontinuous current.
  7. A three-phase half wave controlled rectifier feeding power to RL load at α=60°. Draw output voltage and input current waveform of any one phase.
  8. A Three phase half wave controlled rectifier fed by 150 V/phase supply. Determine load voltage for α=30 and 60 degrees.
  9. Short notes on following
    (a) Cosine firing scheme
    (b) Effect of source impedance on converters
    (c) Three phase semi converters.